I don't think it's a one-time thing though. Madrid has been really inconsistent this season and a lot of times they've been bailed by the individual quality in their squad. Madrid has so much quality that any player can produce a moment of magic at any time and that is what happened against Atleti.
Days when the individual quality doesn't impress or when the opponent play better, they suffer.
I don't think Madrid would be able to win the La liga because they will still drop more points in the league. I agree that the other 2 teams will drop points, but not as much as Madrid. The champions league and Copa del Rey are the only hope of Silverware for Madrid this season.
I'm not sure if I'm the only person that have notice or it's just recent that I came across this, any season that Real Madrid song win El clasico, they hardly win the Laliga trophy, two season before now they lost El clasico to Barcelona and in the end, Barcelona won the league. That means any season Barcelona is able to win the Laliga, they do also have the power to win them in any El clasico so it's very possible that it's too late that this season belongs to Barcelona already.
However, since Barcelona is not far yet with their points, I don't want to think my theory will comfirm this season, there are lot of things and room for many things to happen. Things like having red card and losing match, things like injuries and many more unforseen circumstances that can happen to teams, it can still happen to Barcelona, Real Madrid or even Bilbao. We just have to sit, watch and enjoy more shows that will b coming from April and May.